Undernutrition early in development can produce a permanent intellectual deficit. Although the precise cause of this intellectual impairment is unknown, there is considerable evidence that CNS myelin formation, neuronal development and the formation of synapses are disturbed. Previous work in this laboratory focused on the quantitative and qualitative abnormalities in myelin. The present study will examine the formation and structure of gangliosides and glycoproteins in CNS synaptic plasma membranes. Gangliosides and glycoproteins were chosen for study since these membrane components are known to participate in cell-cell interactions and recognition phenomena. Thus one would expect that an alteration in either the synthesis or structure of these components in synaptic plasma membranes could result in altered synaptic connectivity and permanent neural dysfunction. We will examine the synthesis of gangliosides and glycoproteins in synaptic plasma membranes from control (C) rats and those that were undernourished during either gestation (U-G), lactation (U-L) or lactation and the postweanling period (U-L+W). A double-label isotope technique will be used whereby an 3H-labeled compound (fucose for glycoproteins and N-acetylmannosamine for gangliosides) will be injected intraventricularly into one animal and the 14C-labeled compound will be injected into a second animal. 3H- and 14C-labeled samples will be combined prior to separation on a single gel or on a single chromatography lane. The following pairs of animals will be studied using this technique: C & U-G; C & U-L; C & U-L+W; U-G & U-L; U-L & U-L+W. This double label radioisotope technique facilitates recognition of small compositional differences. The experimental groups will be compared with each other as well as with control rats in order to assess the relative severity and reversibility of each stress.